from random import choice

def get_step():
    direction = choice([1, -1])
    distance = choice([0, 1, 2, 3, 4])
    step = direction * distance
    return step

class RandowWalk():

    def __init__(self, num_points=5000) -> None:
        self.num_points = num_points

        self.x_values = [0]
        self.y_values = [0]

    def fill_walk(self):

        while len(self.x_values) < self.num_points:

            x_step = get_step()
            y_step = get_step()
            # 拒绝原地踏步
            if x_step == 0 and y_step == 0:
                continue

            next_x = self.x_values[-1] + x_step
            next_y = self.y_values[-1] + y_step
            self.x_values.append(next_x)
            self.y_values.append(next_y)
